1. Field of the Invention
The present invention relates to a resistive thermal sensor and method for manufacturing the same, and more particularity to a metallic silicide resistive thermal sensor and method for manufacturing the same.
2. Description of Related Art
A resistive thermal sensor is a device that converts a heat signal into an electrical signal induced by the change of resistance of the device. The applications of the resistive thermal sensor relate to microbolometer infrared sensors, pressure sensors, flowmeters, thermal accelerometers, etc.
For example, the microbolometer infrared sensors manufactured by Honeywell Inc./U.S. and LETI Inc./France are composed of vanadium oxide and amorphous silicon. However, such materials are not compatible for common CMOS manufacturing process. Additional manufacturing processes and equipments are necessary to form such vanadium oxide and amorphous silicon. Therefore, semiconductor manufactories hardly fabricate the microbolometers with such materials at low price. As a result, the cost for manufacturing the microbolometers rises. Moreover, flicker noises generated from such semiconductor materials are higher than those generated from the metallic materials when the microbolometers are activated.
With reference to U.S. Pat. No. 5,698,852, a titanium bolometer-type infrared detecting apparatus is disclosed. The bolometer takes titanium as a conducting medium and the titanium is compatible for common CMOS manufacturing process. However, the low temperature coefficient of resistance (TCR) of titanium is only 0.25%/K and will result in low sensitivity. In addition, the stability of titanium is poorer than that of metallic silicide in high temperature semiconductor processes.